JP2012101241A - Hole processing device and hole processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hole processing device 1 capable of preparing a hole having a large ratio of L/D by decreasing possibility on buckling of a punch, in the hole processing device capable of coping with both productivity and processing quality.SOLUTION: The hole processing device 1 includes a laser oscillator 6 for locally heating a part of a workpiece 3 at a temperature equal to or below the melting point, and a punch drive means 7 for driving the punch 2 toward a part of the heated workpiece 3. Thus, the hole 4 having a large ratio of L/D can be prepared by decreasing possibility on buckling of the punch 2 since the workpiece 3 can be locally softened and the softened section of the workpiece 3 can be pierced with the punch 2. Further, productivity in a process of preparing the hole 4 is not reduced without taking longer processing time since the process simply adds a step of local heating on the workpiece in addition to a step of piercing the workpiece. Processing quality of the workpiece in the process is not also reduced since the hole 4 is prepared with piercing. Consequently, the hole 4 having a large ratio of L/D of the workpiece 3 can be prepared by decreasing possibility on buckling of the punch 2 while coping with both productivity and processing quality in the process.

Description

  The present invention relates to a hole machining apparatus and a hole machining method in which a columnar punch is driven in an axial direction to provide a hole in a workpiece.

  Conventionally, in a hole processing apparatus in which holes are formed by punching with a punch, the risk of punch buckling increases as the ratio of the length L to the diameter D (hereinafter referred to as L / D) increases. Has become an issue. In view of this, a hole machining apparatus that can provide holes by electric discharge machining or laser machining without using a punch has been considered.

  By the way, when a hole is provided by electric discharge machining, there is a problem that the machining time becomes longer than punching and productivity is lowered. Moreover, when providing a hole by laser processing, although the fall of productivity can be avoided, there exists a subject in which process quality, such as a hole's dimensional accuracy and surface property, is inferior compared with punching or electric discharge machining. Therefore, for example, a drilling device described in Patent Document 1 has been proposed for the purpose of achieving both productivity and machining quality.

The hole processing apparatus of Patent Document 1 includes a laser head, a punch, and a die, and provides a hole by using both laser processing and punching. That is, according to the hole drilling device of Patent Document 1, after making a pilot hole in the workpiece by laser processing, the workpiece is punched out with a punch having a diameter larger than that of the pilot hole so as to scrape the periphery of the pilot hole. As a result, the hole drilling device of Patent Document 1 attempts to achieve both productivity and machining quality while reducing the possibility of the buckling of the punch.
However, according to the hole processing apparatus of Patent Document 1, the axial alignment between the formation of the pilot hole by the laser and the punching by the punch is complicated, which is a new problem.

JP 2009-050901 A

  The present invention has been made to solve the above-described problems, and its object is to reduce the possibility of punch buckling in a hole drilling apparatus and a hole drilling method capable of achieving both productivity and machining quality. Thus, it is possible to provide a hole having a large L / D.

[Means of Claim 1]
According to the first aspect of the present invention, the hole drilling device drives the columnar punch in the axial direction to provide a hole in the workpiece.
Further, the hole machining apparatus drives the punch in the axial direction toward a local heating means for locally heating a part of the work in a temperature range below the melting point of the work and a part of the work heated by the local heating means. Punch drive means.

As a result, the workpiece can be locally softened to produce a portion having a small deformation resistance, and a portion having a small deformation resistance can be punched out with a punch. Large holes can be easily provided. In addition, since the step of forming the holes is a punching process using a punch and a local heating of the work is added, the processing time is not so long and the productivity is not lowered. Furthermore, since the hole is provided by punching, the processing quality is not deteriorated.
As described above, it is possible to provide a hole having a large L / D while reducing the possibility of punch buckling in a hole processing apparatus capable of achieving both productivity and processing quality.

  In addition, since the work is not heated and softened as a whole, but locally heated and softened, the deformation area generated in the periphery of the hole due to punching can be reduced, and heating is necessary. Energy can be reduced.

  Further, when a hole is provided by punching, a die having a hole corresponding to the hole provided in the workpiece is usually required (hereinafter, the die side hole is referred to as a die hole), and the position of the hole and the die hole are provided in the workpiece. It is necessary to punch the workpiece by punching with the above. That is, it is necessary to remove the meat portion corresponding to the hole by generating a crack in the work by the die cutting edge by supporting the work with the die cutting edge formed by the peripheral edge of the die hole against the pressing force by the punch.

  On the other hand, according to the means of claim 1, by locally heating and softening the workpiece, the meat portion corresponding to the hole can be removed using the difference in deformation resistance based on the temperature difference. . For this reason, since it is possible to provide a hole in the work without using a die, it is possible to provide a hole without forcibly arranging a die when a work shape where it is difficult to arrange the die is to be drilled. it can.

[Means of claim 2]
According to the means of claim 2, the punch receives a processing load as a reaction force from the workpiece while the workpiece is punched out. The processing load is smaller than the buckling load of the punch due to the softening of the work accompanying the heating of the local heating means.
Thereby, buckling of the punch during punching can be reliably prevented.

[Means of claim 3]
According to the means of claim 3, the local heating means is a laser oscillator, and a part of the workpiece is heated by a laser emitted from the laser oscillator.
Thereby, the setting of the heating area | region, heating temperature, etc. in a workpiece | work can be changed freely.

[Means of claim 4]
According to the means of claim 4, a part of the workpiece has a laser surface that the laser directly hits and a punch surface with which the tip of the punch abuts, and the punch punches the workpiece from the punch surface toward the laser surface. While the hole is formed and the workpiece is punched out, a machining load as a reaction force is received from the workpiece. The laser oscillator sets the heating conditions for the laser so that the laser surface temperature is lower than the melting point of the workpiece and the processing load becomes smaller than the buckling load of the punch due to the softening of the workpiece caused by heating. Has been.
Accordingly, it is possible to reliably prevent the buckling of the punch while preventing the workpiece from melting and the hole diameter accuracy and surface properties from being lowered.

[Means of claim 5]
According to the means of the fifth aspect, the hole drilling apparatus includes a control means for controlling the laser oscillator and the punch driving means. Then, the control means controls the laser oscillator and the punch driving means so that punching of the workpiece by the punch starts after the generation of the laser by the laser oscillator stops and the laser does not hit the laser surface.
This prevents the punch from being damaged by the laser, and the punching can be finished before the deformation resistance increases due to cooling after the laser heating is stopped.

[Means of claim 6]
According to the means of claim 6, the hole drilling method is to provide a hole in the workpiece by driving a columnar punch in the axial direction. Further, the hole drilling method includes a local heating step in which a part of the workpiece is locally heated in a temperature range below the melting point of the workpiece, and a punch is driven in the axial direction toward a part of the workpiece heated in the local heating step. And a punching process for punching a workpiece by punching.
Thereby, the same effect as that of the means of claim 1 can be obtained.

[Means of Claim 7]
According to the seventh aspect, the punch receives a processing load as a reaction force from the workpiece while the workpiece is punched out. The processing load is smaller than the buckling load of the punch due to the softening of the work accompanying the heating in the local heating process.
Thereby, the same effect as that of the means of claim 2 can be obtained.

[Means of Claim 8]
According to the eighth aspect of the present invention, the local heating step is performed using a laser oscillator, and a part of the work is heated by a laser emitted from the laser oscillator.
Thereby, the same effect as that of the means of claim 3 can be obtained.

[Means of Claim 9]
According to the means of the ninth aspect, a part of the work has a laser surface that the laser directly hits and a punch surface with which the tip of the punch abuts, and the punch punches the work from the punch surface toward the laser surface. While the hole is formed and the workpiece is punched out, a machining load as a reaction force is received from the workpiece. The laser oscillator sets the heating conditions for the laser so that the laser surface temperature is lower than the melting point of the workpiece and the processing load becomes smaller than the buckling load of the punch due to the softening of the workpiece caused by heating. Has been.
Thereby, the same effect as that of the means of claim 4 can be obtained.

[Means of Claim 10]
According to the tenth aspect of the present invention, after the laser generation by the laser oscillator is stopped and the laser does not hit the laser surface, punching of the workpiece by the punch in the punching process is started.
Thereby, the same effect as that of the means of claim 5 can be obtained.

(A) is a whole block diagram of a hole processing apparatus, (b) is a principal part block diagram of a hole processing apparatus (Example). It is a time chart which shows the temperature transition in the laser surface and punch surface accompanying the heating start by a laser, and a heating stop (Example). (A) is explanatory drawing which shows the state which mounted the workpiece | work on the work set, (b) is explanatory drawing which shows the state which presses a workpiece | work with a workpiece holder and a punch guide, and is heating the workpiece | work with a laser, (c) is explanatory drawing which shows the state which has punched the workpiece | work with a punch, (d) is explanatory drawing which shows the state which pulled up the punch with the workpiece presser and the punch guide (Example). It is a principal part block diagram of a hole processing apparatus (modification).

  The hole drilling apparatus of the embodiment is configured to provide a hole in a workpiece by driving a columnar punch in the axial direction. Further, the hole machining apparatus drives the punch in the axial direction toward a local heating means for locally heating a part of the work in a temperature range below the melting point of the work and a part of the work heated by the local heating means. Punch drive means.

The punch receives a processing load as a reaction force from the workpiece while the workpiece is punched. The processing load is smaller than the buckling load of the punch due to the softening of the work accompanying the heating of the local heating means.
The local heating means is a laser oscillator, and a part of the workpiece is heated by a laser emitted from the laser oscillator.

  Further, a part of the workpiece has a laser surface directly hit by the laser and a punch surface against which the tip of the punch abuts, and the punch provides a hole by punching the workpiece from the punch surface toward the laser surface. The laser oscillator sets the heating conditions for the laser so that the laser surface temperature is lower than the melting point of the workpiece and the processing load becomes smaller than the buckling load of the punch due to the softening of the workpiece caused by heating. Has been.

  Further, the hole processing apparatus includes a control unit that controls the laser oscillator and the punch driving unit. Then, the control means controls the laser oscillator and the punch driving means so that punching of the workpiece by the punch starts after the generation of the laser by the laser oscillator stops and the laser does not hit the laser surface.

[Configuration of Example]
The structure of the hole processing apparatus 1 of an Example is demonstrated based on FIG.
The hole drilling device 1 drives the columnar punch 2 in the axial direction to provide the workpiece 4 with the hole 4. For example, even when the L / D is 2 or more, the punch 2 does not buckle. It can be provided.

  The hole machining apparatus 1 is used, for example, to provide an injection hole with a body of an injector that injects fuel into a combustion chamber of an internal combustion engine as a work 3, or a plate that forms a back pressure chamber of the injector as a work 3. It is used to provide a flow path for fuel flow into the back pressure chamber. The material of the punch 2 is, for example, cemented carbide obtained by mixing and sintering tungsten carbide and cobalt as a binder.

  The hole processing apparatus 1 has a local heating means 6 for locally heating a part of the work 3 in a temperature range below the melting point of the work 3, and a punch 2 directed toward a part of the work 3 heated by the local heating means 6. A punch driving means 7 for driving in the axial direction, a control means 8 for controlling the local heating means 6 and the punch driving means 7, and a work holding means 9 for holding the work 3 are provided.

Here, the punch driving means 7 includes, for example, an air cylinder 12 that generates a driving force for driving the punch 2.
The work holding means 9 is, for example, a punch guide 13 that slidably holds the tip of the punch 2 and guides the movement of the punch 2 in the axial direction, a work set 14 on which the work 3 is placed, and a punch guide 13. Is held on the inner peripheral side, and includes a work presser 15 and the like for pressing the work 3 placed on the work set 14.

  The work retainer 15 also functions as, for example, a punch holder that slidably holds the rear end 2a of the punch 2. Further, the tip 2b of the punch 2 guided by the punch guide 13 is provided in an elongated shape according to the diameter of the hole 4, and the hole 4 is provided by punching the workpiece 3 by the tip 2b. And the rear-end part 2a is provided larger diameter than the front-end | tip part 2b.

  Further, the rear end surface of the punch guide 13 and the front end surface of the rear end portion 2a are tapered so that the diameter thereof is reduced toward the front end side so that the rear end portion 2a can be fitted to the punch guide 13, for example. It is provided in the shape. Further, the tips of the punch 2, the punch guide 13, and the work retainer 15 are configured to be at the same position in the axial direction when being pulled up from the work 3.

  The local heating means 6 locally softens a part of the work 3 so as not to be melted to locally generate a part having a low deformation resistance, and locally generates a part having a low deformation resistance in the work 3. Thus, the processing load is made smaller than the buckling load of the punch 2. Here, the processing load is a reaction force received from the workpiece 3 while the punch 2 punches the workpiece 3. If the processing load is larger than the buckling load of the punch 2, the punch 2 is buckled. Therefore, the local heating means 6 is heated to soften the workpiece 3 in a range where the workpiece 3 is not melted to reduce deformation resistance, and the processing load is made smaller than the buckling load of the punch 2.

  The local heating means 6 is, for example, a laser oscillator (hereinafter, the local heating means 6 is referred to as a laser oscillator 6), and a part of the workpiece 3 is heated and softened by a laser emitted from the laser oscillator 6. That is, the laser oscillated by the laser oscillator 6 reaches the laser head 18 through the fiber 17, is condensed by the laser head 18 and is irradiated toward the workpiece 3, and the workpiece 3 is heated and softened.

  Here, a part of the work 3 has a laser surface 20 to which the laser directly hits and a punch surface 21 with which the tip of the punch 2 abuts. The punch 2 moves from the punch surface 21 toward the laser surface 20. The hole 4 is provided by punching out. The laser head 18 is arranged so that the tip of the nozzle 22 faces the laser surface 20 of the work 3 placed on the work set 14, and the laser head 18 and the punch 2 are, for example, a laser irradiation axis and The punch 2 is positioned so as to be coaxial with the axis of the punch 2.

For this reason, the workpiece 3 heated by the laser is punched by the punch 2 while remaining in the same place without being moved to another place.
Here, for example, as shown in FIG. 2, the temperature transitions on the laser surface 20 and the punch surface 21 from the start of heating by the laser to the lapse of a predetermined time after stopping the heating increase rapidly with the start of heating and then gradually increase. The slope of the slope gradually decreases, and after a short period of time, when the heating is stopped, the downward slope gradually decreases. For this reason, after stopping heating, the deformation resistance increases rapidly and exceeds the buckling load of the punch 2.

  Therefore, if the heated workpiece 3 is moved to another location and punching with the punch 2 is attempted, the workpiece 3 must be moved very quickly and accurately, and the moving operation becomes complicated. Therefore, for example, the punch 2 and the laser head 18 are arranged so that the axis of the punch 2 and the laser irradiation axis are coaxial so that the punch 2 can be punched without moving the heated work 3. Locating.

  Further, the laser oscillator 6 is configured so that the temperature of the laser surface 20 is equal to or lower than the melting point of the workpiece 3 and the processing load becomes smaller than the buckling load of the punch 2 due to the softening of the workpiece 3 due to heating by the laser. Heating conditions such as power, frequency, duty ratio, heating time (irradiation time), and defocus (focal length) are set.

  That is, during the heating by the laser, the temperature of the laser surface 20 is the highest in the workpiece 3, and the melting of the workpiece 3 is most likely to occur in the laser surface 20. Therefore, the heating conditions by the laser oscillator 6 are set so that the temperature of the laser surface 20 is equal to or lower than the melting point of the workpiece 3 and the processing load is smaller than the buckling load of the punch 2.

  In addition, it is preferable that the heating area on the laser surface 20 is small from the viewpoint of reducing the deformation area generated in the periphery of the hole 4 due to punching and reducing the energy required for heating. Therefore, for example, the laser spot diameter is set to about 10 times the diameter of the punch 2.

  The control means 8 is provided so as to constitute, for example, a microcomputer that outputs a control signal for driving and controlling the laser oscillator 6, the punch driving means 7 and the like based on detection signals input from various sensors. That is, the control means 8 includes a CPU that performs control processing and arithmetic processing, a storage device such as a ROM and a RAM that stores various data and programs, an input device, an output device, and the like.

  Then, the control means 8 controls the laser oscillator 6 and the punch driving means 7 so that punching of the workpiece 3 by the punch 2 starts after the generation of the laser by the laser oscillator 6 stops and the laser does not hit the laser surface 20. To do. In other words, the control means 8 controls the laser oscillator 6 and the punch so that the punch 2 is not damaged by the laser irradiation and the punching is finished before the deformation resistance exceeds the buckling load of the punch 2 after the heating by the laser is stopped. The drive means 7 is controlled.

  That is, there is a time lag after the control signal for driving the punch 2 is output from the control means 8 to the punch driving means 7 until the punch 2 actually contacts the work 3 and starts punching. For example, when the punch driving means 7 is an air cylinder 12, output of a control signal → start of energization to the solenoid valve 23 for turning on / off introduction of high pressure air → start of operation of the air cylinder 12 accompanying introduction of high pressure air → by punch 2 A time lag occurs due to the steps such as the start of punching.

  Therefore, in consideration of the time lag, the control means 8 monitors the elapsed time from the start of laser generation so that, for example, a control signal for driving the punch 2 is output a predetermined time before the laser generation stop. Is set.

[Processing method of Example]
The processing method by the hole processing apparatus 1 of an Example is demonstrated using FIG.
The machining method by the hole machining apparatus 1 is directed to a local heating process in which a part of the work 3 is locally heated by the laser oscillator 6 in a temperature range below the melting point of the work 3 and a part of the work 3 heated by the local heating process. The punching means 7 drives the punch 2 in the axial direction and punches the workpiece 3 with the punch 2.
Hereinafter, the processing method by the hole processing apparatus 1 will be described focusing on the local heating process and the punching process.

  First, the workpiece 3 is set on the workpiece holding means 9 before the local heating step. That is, the work 3 is placed on the work set 14 (see FIG. 3A), and the work 3 placed on the work set 14 is pressed and held by the work presser 15 (see FIG. 3B).

  Next, the local heating process is started by operating the laser oscillator 6. Thereby, the laser is irradiated to form a predetermined laser spot diameter on the laser surface 20 of the workpiece 3 (see FIG. 3B), and the workpiece 3 is heated and softened to such an extent that a part of the workpiece 3 is not melted. The deformation resistance becomes smaller than the buckling load of the punch 2 in a part of Simultaneously with the start of laser generation by the laser oscillator 6, time monitoring for the start of driving of the punch 2 is started.

  Then, after the time set by the time monitoring means has elapsed, a control signal for driving the punch 2 is output from the control means 8 to the punch drive means 7, and subsequently, the set heating time has elapsed, and the laser Laser generation by the oscillator 6 is stopped. As a result, the temperature of the workpiece 3 once increased starts to decrease, and the deformation resistance starts to increase.

  Eventually, the punching process is started in response to the output of a control signal for driving the punch 2. That is, the punch 2 is driven toward the workpiece 3 in accordance with the output of the control signal, and punching starts. At this time, the laser does not hit the laser surface 20, and the situation where the laser hits the punch 2 is avoided. Then, the punching is completed before the workpiece 3 is too cold and the deformation resistance exceeds the buckling load of the punch 2 (see FIG. 3C), and the punch 2 is pulled up (see FIG. 3D).

[Effects of Examples]
The hole drilling apparatus 1 of the embodiment has a laser oscillator 6 that locally heats a part of the work 3 in a temperature range below the melting point of the work 3, and a punch 2 that is directed toward a part of the work 3 heated by the laser. Punch drive means 7 for driving in the direction.
As a result, the workpiece 3 is locally softened to locally produce a portion having a small deformation resistance, and the portion having a small deformation resistance can be punched with the punch 2, thereby reducing the possibility of buckling of the punch 2. The hole 4 having a large L / D can be easily provided.

In addition, the process of providing the holes 4 is a punching process using the punch 2 with local heating of the work 3 added thereto, so that the processing time is not so long and the productivity is not lowered. Furthermore, since the hole 4 is provided by punching, the processing quality does not deteriorate.
As described above, in the hole drilling apparatus 1 capable of achieving both productivity and machining quality, it is possible to reduce the risk of buckling of the punch 2 and provide the hole 4 having a large L / D.

  In addition, since the work 3 is not heated and softened as a whole, but locally heated and softened, the deformation region generated in the periphery of the hole 4 due to punching can be reduced, and heating can be performed. The required energy can be reduced.

  Furthermore, when the hole 4 is provided by punching, a die is usually required, and it is necessary to punch the workpiece 3 with the punch 2 after matching the position where the hole 4 is provided in the workpiece 3 and the die hole. That is, the workpiece 3 is supported by the die cutting edge formed by the peripheral edge of the die hole against the pressing force by the punch 2, so that a crack is generated in the workpiece 3 by the die cutting edge and the meat portion corresponding to the hole 4 is removed. There is a need.

On the other hand, according to the hole processing apparatus 1, the workpiece 3 is locally heated and softened to remove the meat portion corresponding to the hole 4 using the difference in deformation resistance based on the temperature difference. it can. For this reason, since the hole 4 can be provided in the workpiece 3 without using a die, when the shape of the workpiece 3 is difficult to arrange the die, the hole 4 is provided without excessively arranging the die. Can do.
Moreover, since a part of the workpiece 3 is heated by the laser emitted from the laser oscillator 6, the setting of the heating region, the heating temperature, etc. in the workpiece 3 can be freely changed.

Further, the laser oscillator 6 is configured so that the temperature of the laser surface 20 is equal to or lower than the melting point of the workpiece 3 and the processing load becomes smaller than the buckling load of the punch 2 due to the softening of the workpiece 3 caused by heating. The heating conditions are set.
Thereby, the buckling of the punch 2 can be surely prevented while avoiding the workpiece 3 from being melted and the hole diameter accuracy and surface properties being lowered.

Further, the control means 8 monitors the elapsed time from the start of laser generation so that punching of the workpiece 3 by the punch 2 starts after the laser generation by the laser oscillator 6 stops and the laser no longer hits the laser surface 20. Have means.
Thereby, the punch 2 can be prevented from being damaged by the laser, and the punch 2 can be punched before the deformation resistance is increased by cooling after the laser heating is stopped.

[Modification]
The mode of the hole machining apparatus 1 is not limited to the embodiment, and various modifications can be considered.
For example, according to the hole drilling apparatus 1 of the embodiment, the laser oscillator 6 is used as the local heating means. However, as shown in FIG. You may make it soften by heating. That is, the electrodes 25 and 26 and the insulating materials 27 and 28 are disposed on the work set 14 and the work retainer 15, respectively, and a part of the work 3 is sandwiched between the electrodes 25 and 26, and a part of the work 3 is energized. A part of 3 may be heated and softened.

DESCRIPTION OF SYMBOLS 1 Hole processing apparatus 2 Punch 3 Workpiece 4 Hole 6 Laser oscillator (local heating means)
7 Punch drive means 8 Control means 20 Laser surface 21 Punch surface

Claims (10)

In the hole drilling device in which the columnar punch 2 is driven in the axial direction to provide the hole 4 in the workpiece 3,
Local heating means 6 for locally heating a part of the workpiece 3 in a temperature range equal to or lower than the melting point of the workpiece 3;
A hole drilling device comprising punch driving means 7 for driving the punch 2 in an axial direction toward a part of the workpiece 3 heated by the local heating means 6. The hole drilling apparatus according to claim 1,
While the punch 2 is punching the workpiece 3, the punch 2 receives a processing load as a reaction force from the workpiece 3.
The hole machining apparatus according to claim 1, wherein the machining load is smaller than a buckling load of the punch 2 due to softening of the workpiece 3 accompanying heating of the local heating means 6. In the hole drilling device according to claim 1 or 2,
The local heating means 6 is a laser oscillator 6;
A part of the workpiece (3) is heated by a laser emitted from the laser oscillator (6). In the hole drilling device according to claim 3,
A part of the workpiece 3 has a laser surface 20 that a laser directly hits, and a punch surface 21 with which the tip of the punch 2 abuts.
The punch 2 is provided with the hole 4 by punching the workpiece 3 from the punch surface 21 toward the laser surface 20. While the workpiece 3 is being punched, a work load as a reaction force is applied from the workpiece 3. received,
In the laser oscillator 6, the processing load is smaller than the buckling load of the punch 2 due to the softening of the work 3 caused by heating so that the temperature of the laser surface 20 is lower than the melting point of the work 3. As described above, a hole processing apparatus in which a heating condition by a laser is set. The hole drilling apparatus according to claim 4, wherein
A control means 8 for controlling the laser oscillator 6 and the punch driving means 7;
The control means 8 includes the laser oscillator 6 and the punch so that punching of the workpiece 3 by the punch 2 starts after the laser generation by the laser oscillator 6 stops and the laser does not hit the laser surface 20. A drilling device that controls the driving means 7. In the hole machining method in which the columnar punch 2 is driven in the axial direction to provide the workpiece 4 with the hole 4,
A local heating step of locally heating a part of the workpiece 3 in a temperature range below the melting point of the workpiece 3;
A punching method comprising: a punching step of driving the punch 2 in an axial direction toward a part of the workpiece 3 heated by the local heating step and punching out the workpiece 3 by the punch 2. The hole drilling method according to claim 6, wherein
While the punch 2 is punching the workpiece 3, the punch 2 receives a processing load as a reaction force from the workpiece 3.
The hole machining method according to claim 1, wherein the machining load is smaller than a buckling load of the punch 2 due to softening of the workpiece 3 accompanying heating in the local heating step. In the hole drilling method according to claim 6 or 7,
The local heating step is performed using a laser oscillator 6;
A part of the workpiece (3) is heated by a laser emitted from the laser oscillator (6). The hole drilling method according to claim 8, wherein
A part of the workpiece 3 has a laser surface 20 that a laser directly hits, and a punch surface 21 with which the tip of the punch 2 abuts.
The punch 2 is provided with the hole 4 by punching the workpiece 3 from the punch surface 21 toward the laser surface 20. While the workpiece 3 is being punched, a work load as a reaction force is applied from the workpiece 3. received,
In the laser oscillator 6, the processing load is smaller than the buckling load of the punch 2 due to the softening of the work 3 caused by heating so that the temperature of the laser surface 20 is lower than the melting point of the work 3. As described above, a heating condition by a laser is set. The hole drilling method according to claim 9, wherein
A hole drilling method characterized by starting punching of the work 3 by the punch 2 in the punching step after generation of laser by the laser oscillator 6 is stopped and the laser does not hit the laser surface 20.

Images